As a matter of experience do what ever you can on set. The “fix it in post” may and will give you problems. Why not shoot the scene twice, once with the DP light raking and then again without. That way if it doesn’t work in AE you have a safety net. The problem I see with doing it in AE is that you have depth and background inside the car to deal with, along with having to isolate travelling mattes to light the foreground actors, etc… Best to do it when shooting as suggested by your DP.